Aluminum-steel electric arc material increasing method based on laser cladding nickel-based alloy middle layer

Abstract

The invention relates to an aluminum-steel heterogeneous bimetallic structure electric arc additive manufacturing method based on a laser cladding nickel-based alloy middle layer, and belongs to the field of metal additive manufacturing. According to the method, firstly, a nickel-based alloy intermediate layer is prepared on the surface of a steel substrate through a laser cladding process, and generation of brittle intermetallic compounds during direct combination of aluminum and steel is effectively inhibited; and then aluminum alloy is deposited layer by layer on the middle layer through the electric arc additive manufacturing technology, and reliable forming of the aluminum-steel heterostructure is achieved. Through the transition and barrier effects of the nickel-based middle layer, the aluminum-steel interface bonding performance is remarkably improved, the mechanical strength and service reliability of the overall structure are improved, and an innovative process path is provided for integrated forming of light-weight composite components in the fields of aerospace, automobile manufacturing and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal arc additive manufacturing, in particular to an aluminum-steel heterogeneous bimetallic structure arc additive manufacturing method based on laser cladding of a nickel-based alloy intermediate layer. BACKGROUND

[0002] With the increasing demand for lightweight of high-end equipment such as aerospace and new energy vehicles, aluminum-steel heterogeneous bimetallic structures have become a research and application hotspot because they can comprehensively exert the respective advantages of aluminum alloy lightweight and steel structure high strength. The arc additive manufacturing technology provides a highly potential technical route for manufacturing large-size and high-performance aluminum-steel composite structures due to its high deposition efficiency, low cost and ability to form complex components. Realizing reliable connection and integrated forming of aluminum-steel is of great significance to promote the deep integration of lightweight design and intelligent manufacturing technology.

[0003] However, in the practice of aluminum-steel arc additive manufacturing, there are severe challenges. Aluminum and steel have great differences in physical properties (such as melting point, thermal expansion coefficient) and crystal structure, resulting in poor compatibility. More importantly, under the action of arc heat source, aluminum and iron elements will diffuse and react violently, generating a large amount of hard and brittle Fe-Al intermetallic compounds (such as , ) at the bonding interface. These brittle phases will seriously weaken the interface bonding strength, making the component prone to cracking failure at the interface during service.

[0004] In existing additive manufacturing technologies, in order to inhibit the generation of brittle intermetallic compounds at the aluminum-steel interface, the intermediate layer used in actual industry is mostly metal foil. In aluminum-steel additive manufacturing, the metal foil as the intermediate layer cannot effectively solve the brittleness of the compound through metallurgical means, resulting in weak bonding, while laser cladding can form a tough transition layer through metallurgical bonding, fundamentally realizing strong and tough connection. SUMMARY

[0005] The purpose of the present application is to provide an aluminum-steel heterogeneous bimetallic structure arc additive manufacturing method based on laser cladding of a nickel-based alloy intermediate layer. The method of the present application can significantly block the direct diffusion of aluminum and iron to generate brittle intermetallic compounds, thereby improving the mechanical properties of the aluminum-steel heterogeneous bimetallic structure.

[0006] The following technical solutions can achieve the purpose of the present application:

[0007] Step 1: pretreat the substrate 1;

[0008] Step 2: laser cladding a nickel-based alloy intermediate layer 2 of different thicknesses on the substrate 1;

[0009] Step 3: Fixing the substrate 1 with the nickel-based alloy interlayer 2 to the fixture device;

[0010] Step 4: Using a cold metal transfer welding heat source to additively obtain an aluminum alloy layer 3 on the nickel-based alloy interlayer 2; preferably, in the step 1, the selected substrate 1 is 316L stainless steel.

[0011] Preferably, in the step 1, after polishing with 120# sandpaper, the surface of the substrate 1 is cleaned with alcohol.

[0012] Preferably, in the step 2, the selected laser cladding conditions are: slice layer thickness 0.010mm, laser power 100W, scanning speed 1000mm / s, energy density 1000J / mm³, grid size 10mm, scanning interval 0.1mm, and spot compensation 50μm.

[0013] Preferably, in the step 2, the selected nickel-based alloy is Inconel625, and the spherical particle size is 9~37μm.

[0014] Preferably, in the step 2, the thickness of the nickel-based alloy interlayer 2 is set to: 25~35μm, 45~55μm, 75~85μm, 95~105μm.

[0015] Preferably, in the step 4, the selected cold metal transfer welding conditions are: mode CMT+Advance+P, welding speed 5.5~6.5mm / s, wire feeding speed 3.5~4.5m / min, and protective gas flow rate 12~17L / min.

[0016] Preferably, in the step 4, the selected protective gas is argon with a purity of 99.99%.

[0017] Preferably, in the step 4, the additive welding wire selected is ER4043 aluminum alloy, the wire diameter is 1.2mm, and the dry extension calibration method of the welding gun uses a reference control calibration to ensure that the dry extension is always 9~12mm.

[0018] Compared with the prior art, the main beneficial effects of the present application are as follows:

[0019] 1. By using laser cladding technology to pre-prepare a nickel-based alloy transition layer on the steel, taking advantage of the characteristics that nickel and aluminum can form intermetallic compounds with good toughness, and nickel and iron can achieve stable metallurgical bonding, the direct reaction between aluminum and iron to form coarse and brittle Fe-Al compounds is effectively blocked and slowed down, thereby fundamentally solving the core problem of easy cracking of the aluminum-steel interface, and significantly improving the bonding strength and toughness of the interface.

[0020] 2. This method ingeniously combines the advantages of two additive manufacturing technologies: the high precision and controllable heat input characteristics of laser cladding are used to “accurately prepare” an interface with a composition and performance optimized metallurgical transition zone, ensuring interface quality; subsequent arc additive manufacturing of aluminum alloy fully utilizes its high deposition efficiency, low cost and suitability for large size forming. This “laser-arc” composite additive strategy ensures high performance of the heterogeneous interface while taking into account the overall manufacturing efficiency, providing a feasible path for the manufacture of large-size, high-performance aluminum-steel composite structures. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the CMT arc additive process of the present application;

[0022] Figure 2 is a comparison chart of the maximum shear strength of embodiments 3-6 and comparative example 1 of the present application;

[0023] Figure 3 is a SEM image of the nickel-based alloy interlayer 2 of the present application without addition;

[0024] Figure 4 is a SEM image of the nickel-based alloy interlayer 2 of the present application with addition.

[0025] In the figure, 1 is the substrate, 2 is the nickel-based alloy interlayer, and 3 is the aluminum alloy layer. DETAILED DESCRIPTION

[0026] To better illustrate the purpose, technical scheme and advantages of the present application, the present application will be described in detail below in combination with the drawings and specific embodiments. The specific embodiments of the present application are described in detail as follows:

[0027] The main purpose of the present application is to provide an aluminum-steel arc additive method based on laser cladding nickel-based alloy interlayer.

[0028] Example 1, this embodiment mainly discloses the final form of the structure to be realized by the method.

[0029] Please refer to Figure 1 , specifically, it includes a substrate 1, and a nickel-based alloy interlayer 2 disposed on the substrate 1, and an aluminum alloy layer 3 deposited on the nickel-based alloy interlayer 2.

[0030] Example 2, this embodiment is mainly used to disclose an aluminum-steel arc additive method based on laser cladding nickel-based alloy interlayer.

[0031] The specific method is as follows:

[0032] Step 1: Pretreat the substrate 1.

[0033] In one preferred embodiment, the substrate 1 is 316L stainless steel, with a composition of C 0.03, Si 1.00, Mn 2.00, P 0.05, S 0.03, Cr 18.00, Ni 14.00, Mo 2.50, Fe balance, in mass percent (%).

[0034] The pre-treatment includes the following steps: polishing the surface oxides with 120# sandpaper, cleaning the surface of the substrate 1 with alcohol, and drying and placing it on the platform of the laser cladding device.

[0035] Step 2: Cladding a nickel-based alloy intermediate layer 2 on the substrate 1.

[0036] First, the nickel-based alloy powder with a particle size of 9-37 μm, which is Inconel 625, is placed in the powder bin of the laser cladding device. The laser cladding conditions are: slice layer thickness 0.010 mm, laser power 100 W, scanning speed 1000 mm / s, energy density 1000 J / mm³, grid size 10 mm, scanning interval 0.1 mm, and spot compensation 50 μm. Under these conditions, a nickel-based alloy intermediate layer 2 with a thickness of 30 μm, 50 μm, 80 μm, or 100 μm is laser cladded on the substrate 1.

[0037] Step 3: Fixing the substrate 1 with the nickel-based alloy intermediate layer 2 of different thicknesses on the fixture device.

[0038] Step 4: Additively manufacturing an aluminum alloy layer 3 on the nickel-based alloy intermediate layer 2.

[0039] The specific method steps are: single-pass single-layer arc additive manufacturing is performed using a cold metal transfer welding heat source, the vertical direction of the surface of the 316L stainless steel substrate 1 is the deposition direction, the length direction of the surface of the substrate 1 is the additive manufacturing travel direction, and the deposition material is ER4043 welding wire with a diameter of 1.2 mm, which has a composition of Si 5.00, Mn 0.05, Cu 0.30, Fe 0.80, Zn 0.10, and Al balance, in mass percent (%). During the additive manufacturing process, argon gas with a purity of 99.99% is used as the protective gas, and the protective gas flow rate is 12-17 L / min; the welding torch is initiated from the right side starting position and begins to deposit by sending the wire, and is extinguished at the left side end position. The welding torch travels in a straight line, the dry extension of the welding torch is calibrated by a reference object, and the dry extension is controlled to be within the range of 9-12 mm. The cold metal transfer welding mode selected is CMT+Advance+P, the welding speed is 5.5-6.5 mm / s, and the wire feeding speed is 3.5-4.5 m / min. Thus, the aluminum alloy layer 3 is additively manufactured on the nickel-based alloy intermediate layer 2 according to the above method.

[0040] The sandpaper, chemical reagents and the like used in the following examples are commercially available reagents and materials.

[0041] Example 3

[0042] The substrate 1 has a size of 100 mm x 50 mm x 5 mm. After polishing the surface oxide with 120# sandpaper, the surface of the substrate 1 is cleaned with alcohol. The Inconel 625 nickel-based alloy intermediate layer 2 is laser cladded on the surface of the substrate 1. The laser cladding process parameters are: laser power 100 W, scanning speed 1000 mm / s, energy density 1000 J / mm³, scanning interval 0.1 mm, and spot compensation 50 μm. The final intermediate layer has a thickness of 25-35 μm. After cladding, the steel plate is fixed on the fixture device for CMT arc additive manufacturing. The process parameters are: ER4043 aluminum alloy with a wire diameter of 1.2 mm is used, the protective gas is 99.99% argon with a flow rate of 12-17 L / min, the CMT+Advance+P mode is selected, the welding speed is 5.5-6.5 mm / s, and the wire feeding speed is 3.5-4.5 m / min. The aluminum alloy layer 3 is successfully prepared on the transition layer. After subsequent mechanical testing, the shear strength of the component is only 75.3 MPa.

[0043] Example 4

[0044] The substrate 1 has a size of 100 mm x 50 mm x 5 mm. After polishing the surface oxide with 120# sandpaper, the surface of the substrate 1 is cleaned with alcohol. The Inconel 625 nickel-based alloy intermediate layer 2 is laser cladded on the surface of the substrate 1. The laser cladding process parameters are: laser power 100 W, scanning speed 1000 mm / s, energy density 1000 J / mm³, scanning interval 0.1 mm, and spot compensation 50 μm. The final intermediate layer has a thickness of 45-55 μm. After cladding, the steel plate is fixed on the fixture device for CMT arc additive manufacturing. The process parameters are: ER4043 aluminum alloy with a wire diameter of 1.2 mm is used, the protective gas is 99.99% argon with a flow rate of 12-17 L / min, the CMT+Advance+P mode is selected, the welding speed is 5.5-6.5 mm / s, and the wire feeding speed is 3.5-4.5 m / min. The aluminum alloy layer 3 is successfully prepared on the transition layer. After subsequent mechanical testing, the shear strength of the component is only 90.5 MPa.

[0045] Example 5

[0046] The substrate 1 has a size of 100 mm x 50 mm x 5 mm, and after polishing the surface oxide with 120# sandpaper, the surface of the substrate 1 is cleaned with alcohol. The Inconel 625 nickel-based alloy intermediate layer 2 is laser cladded on the surface of the substrate 1, single pass cladding, and the laser cladding process parameters are: laser power 100 W, scanning speed 1000 mm / s, energy density 1000 J / mm3, scanning interval 0.1 mm, spot compensation 50 μm, and finally an intermediate layer with a thickness of 75-85 μm is prepared. After cladding the steel plate, it is fixed on the fixture device, and CMT arc additive manufacturing is carried out, and the process parameters are: ER4043 aluminum alloy with a wire diameter of 1.2 mm is used, the protective gas is 99.99% argon with a flow rate of 12-17 L / min, the CMT+Advance+P mode is selected, the welding speed is 5.5-6.5 mm / s, and the wire feeding speed is 3.5-4.5 m / min, and finally an aluminum alloy layer 3 is successfully prepared on the transition layer. After subsequent mechanical testing, the shear strength of the component reaches 116.2 MPa.

[0047] Example 6

[0048] The substrate 1 has a size of 100 mm x 50 mm x 5 mm, and after polishing the surface oxide with 120# sandpaper, the surface of the substrate 1 is cleaned with alcohol. The Inconel 625 nickel-based alloy intermediate layer 2 is laser cladded on the surface of the substrate 1, single pass cladding, and the laser cladding process parameters are: laser power 100 W, scanning speed 1000 mm / s, energy density 1000 J / mm3, scanning interval 0.1 mm, spot compensation 50 μm, and finally an intermediate layer with a thickness of 95-105 μm is prepared. After cladding the steel plate, it is fixed on the fixture device, and CMT arc additive manufacturing is carried out, and the process parameters are: ER4043 aluminum alloy with a wire diameter of 1.2 mm is used, the protective gas is 99.99% argon with a flow rate of 12-17 L / min, the CMT+Advance+P mode is selected, the welding speed is 5.5-6.5 mm / s, and the wire feeding speed is 3.5-4.5 m / min, and finally an aluminum alloy layer 3 is successfully prepared on the transition layer. After subsequent mechanical testing, the shear strength of the component reaches 116.2 MPa.

[0049] Comparative Example 1

[0050] The substrate 1 has a size of 100 mm x 50 mm x 5 mm, and after polishing the surface oxide with 120# sandpaper, the surface of the substrate 1 is cleaned with alcohol. The substrate 1 is fixed on the fixture device, and CMT arc additive manufacturing is performed, and the process parameters are as follows: ER4043 aluminum alloy with a wire diameter of 1.2 mm is used, the protective gas is 99.99% argon with a flow rate of 12-17 L / min, the CMT+Advance+P mode is selected, the welding speed is 5.5-6.5 mm / s, the wire feeding speed is 3.5-4.5 m / min, and the aluminum alloy layer 3 is successfully prepared on the transition layer. After subsequent mechanical testing, the shear strength of the component reaches 105.6 MPa.

[0051] From the data of the above examples 3 to 6 and comparative example 1, in the present application, the nickel-based alloy intermediate layer 2 is cladded on the substrate 1 by the method of laser cladding, and then the ER4043 aluminum alloy single layer is deposited on the surface of the nickel-based alloy intermediate layer 2 on the substrate 1. The nickel-based alloy intermediate layer 2 is used as the intermediate layer for CMT arc additive manufacturing, and it is found that under a certain thickness, the nickel-based alloy intermediate layer 2 acts as a buffer zone, effectively preventing the mutual diffusion of Fe and Al elements, inhibiting the formation of Fe-Al intermetallic compounds in the aluminum-steel CMT arc additive manufacturing, and improving the shear strength of the interface.

Claims

1. An arc additive manufacturing method for aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer, characterized in that, The method comprises the following steps: Step 1: pretreating the substrate (1); Step 2: laser cladding a nickel-based alloy intermediate layer (2) of different thicknesses on the substrate (1); Step 3: fixing the substrate (1) on which the nickel-based alloy intermediate layer (2) is cladded to a fixture device; Step 4: using a cold metal transfer welding heat source to additively obtain an aluminum alloy layer (3) on the nickel-based alloy intermediate layer (2).

2. The method of laser arc additive manufacturing of aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer according to claim 1, characterized in that, In the step 1, the substrate (1) is selected to be 316L stainless steel.

3. The method of laser arc additive manufacturing of aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer according to claim 1, characterized in that, In the step 1, after polishing with 120# sandpaper, the surface of the substrate (1) is cleaned with alcohol.

4. The method of laser arc additive manufacturing of aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer according to claim 1, characterized in that, In the step 2, the laser cladding conditions selected are: slice layer thickness 0.010 mm, laser power 100 W, scanning speed 1000 mm / s, energy density 1000 J / mm³, grid size 10 mm, scanning interval 0.1 mm, and spot compensation 50 μm.

5. The method of laser arc additive manufacturing of aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer according to claim 1, characterized in that, In the step 2, the nickel-based alloy selected is Inconel625, and the spherical particle size is 9-37 μm.

6. The method of laser arc additive manufacturing of aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer according to claim 1, characterized in that, In the step 2, the thickness of the nickel-based alloy intermediate layer (2) is set to be: 25-35 μm, 45-55 μm, 75-85 μm, and 95-105 μm.

7. The method of laser arc additive manufacturing of aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer according to claim 1, characterized in that, In the step 4, the cold metal transfer welding conditions selected are: mode CMT+Advance+P, welding speed 5.5-6.5 mm / s, wire feeding speed 3.5-4.5 m / min, and protective gas flow rate 12-17 L / min.

8. The method of laser arc additive manufacturing of aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer according to claim 1, characterized in that, In the step 4, the protective gas selected is argon with a purity of 99.99%.

9. The method of laser arc additive manufacturing of aluminum-steel dissimilar bimetallic structures based on laser cladding of a nickel-based alloy interlayer according to claim 1, characterized in that, In the step 4, the additive welding wire selected is ER4043 aluminum alloy, the wire diameter is 1.2 mm, the welding gun dry elongation calibration method adopts reference control calibration, and the dry elongation is ensured to be always 9-12 mm.

Images